NEW DELHI (AFP) - India warned airlines on Friday (May 29) that passenger flights could be disrupted and planes damaged by the unprecedented locust swarms currently plaguing large stretches of the country.

The worst insect invasion in nearly three decades has already caused massive damage to seasonal crops, crippling Indian farmers struggling with the impact of a months-long national coronavirus lockdown.

But the swarms have now become so large that the civil aviation ministry said they "pose a threat to aircraft in the critical landing and take off phase of the flight".

"Though an individual locust is small in size, impact of large numbers on the windshield is known to have impacted the pilot forward vision," said an advisory from the ministry.

The ministry urged airlines to avoid any swarms, which had the potential to enter air inlets and damage flight instruments.

Experts warn the locust plague could get worse with more insects expected to reach India from the Horn of Africa next month.